Art of distillation of hydrocarbon oils



G. W. WATTSl ART OF` DISTILLATION OF HYDROGARBON OILS Nov. 10,

4 Sheets-Sheet 1 Filed March 24, 1928 .fm/zw@ 30 534/5 WFM? 19.90F@

Nov. 10, 1931. G. w. wA'rTs 1,831,051

ART oF nIsTILLATIoN oF HYDRocARBoN oILs Filed Mach 24, 192s 4 vsheets-smeet 2 STEAM L /N' -i Ja 521D; {fwn- Il'l-zr- .Br- PAss NOV. 10, 1931. G W, WATTS 1,83L051 ART OF DISTILLATION OF HYDROCARBON OILS Filed March 24, 1928 4 sheets-sheet 5 @o 5f @www,ffmMENEMumlwlfV Q20 ejms,

Nov. 1o, l1931. G. w. WATTS 1,831,051

ART OF DISTILLATIN 0F HYDROCRBON OILS l Filed March 24, 192e V4 sheets-'sheet 4 Patented Nov. l0, 1931 UNITED-STATES PATENToFFicE n,

GEORGE W. WATTS, 0F WHITING, INDIANA, ASSIGNOR TO STANDARD OIL COMPANY, 0F WHITING, INDIANA, A CORPORATION OF INDIANA vview of a pipe still;

v construction maybe employed.

ART F DISTILLATION HYDROCARBON OILS Application filed March 24, 1928. Serial No. 264,538.

The present invention relates to improvements in the art of distillation of hydrocarbon oils, andl morel particularly to the pipe still distillation thereof. It will be fully understood from' the following description illustrated by the accompanying drawings, in which:

Figure 1 is a side elevation of apparatus embodying the present invention, shown in conjunction with a diagrammatic sectional Fig. 2 is a detailed sectional view of `a remixing device used in connection with the present invention;

Fig. 3 is a plan view of the apparatus shown in Fig. 1; N

Fig. 4 is an` end elevation thereof with the surge tank and the direct connections thereto removed, as indicated by line 4 in Fig. 3; and

Fig. 5 is a detail sectional view of the surge tank.

Referring more particularly to the drawings, the numeral indicates diagrammatically a pipe still `provided with a bridge wa'll f' 11 dividing' the furnace into a combustion chamber 12, and a convection section 13 through which the combustion gases pass on their way to the stack. It is to be understood that the showing of the pipe still furnace and layout is intended to `loe diagrammatic only,

and that any commercial form' of pipe still In the operation of the pipe stilllin accordance with the present invention, the oil is caused to flow through pipes in a selected port-ion of the furnace until brought to tem-l perature at which Vaporization occurs.` In its subsequent flow through the pipe still, the stream of oil may be divided,and may pass through serially connected pipes in parallel or in a single series, as desired. In the embodim'ent shown in the drawings,- the initial Y portion of. the path of the oil. is in a single strearnthrough series connected pipes and the remainder of its fiow isp-in parallel 4flow in a plurality of ,streams through series connected pipes. However, as. y.willbe readily apparent from the description hereinafter, the invention is not llimited to lsuch a ilowof the oil.

`tillation of Mid-Continent pipe still diagramoil to be distilled, reduced crude oil l ysuch as, for example, a pressed distillate ora 30 to 35% residuumI from a non-cracking dispetroleum is forced into the pipe still through the pipe 14 and passes in series through the pipesv 16 arranged in the convection section 13 of the furnace, in .which they are exposed `to the heating effect of the combustion gases. The oil, 1n passing through the pipes 16, is brought to a temperature at which some vaporization takes place under the existing pressure, which is essentially that required to overcome frictional resistance flow through the pipes although it may be higher. The oil and vapors, which at this point are unevenly intermixed, are caused to llow through the pipe '17 controlled by valve 18 into and through the pipe 19 which leads to the surge tank 20. In the surge tank, Vapor and unvaporized oil are separated, the surge tank'being of substantial capacity, 4so that a considerable body of unvaporized oil is mainvtained 1n the surge tank. The level of oil in the tank may be approximately determined by means of the evenly spaced test lines 21 controlled by cocks 22, which discharge into the line 23. Any oil thus dischargedin test- 80 ing the level of the unvaporized oil in the surge tank passes through the water. cooled section 24 so as to be discharged below a temperature at which it will ignite spontaneously.

The surge tank 20 is provided with anoil discharge line 25,.provided within the tank witha downWardlydirected inlet 26. The discharge line 25 is also'provided within the tank with a connecting risery 27 l`,extending 9o into thevapor space of the tank. lThe oil discharged through the line 25 passesto the 4 The further course of theloil through the furnace is in a plurality of streams in paral- In.

lel, each stream passing through a plurality of the roof tubes 32 in series.

For each of the streams of oil flowing in parallel', a mixer 33 is provided, vapor (and steam, if employed) being fed to the mixer 33 from the vapor header 30 through connections 34 controlled by valve 35. Oil is supplied to each mixer from the oil header or manifold 28 through a connection 36 controlled by valve 37 and terminating within the mixer i n a ti or nozzle 38. The feed of the oil in each mixer is facilitated by the aspirating action of the current of vapors passing therethrough. In each mixer a substantially uniform mixture of vapor and oil is produced, the uniformity of which is not appreciably affected by any reasonable variation of level of the oil in the surge tank 20.

From each mixer 33 the mixed vapors and oil pass through a connection 39 into the series-connected pipes 32, and the parallel streams of oil are discharged into the discharge manifold 40, from which the heated oil passes to a flash drum (not shown) or other suitable separating or fractionating device.

In order to equalize pressure conditions, a vent pipe 41 is provided leading from the oil header 28 to the vapor space in the `upper portion of the surge tank 20.

If it is not desired to use the surge tank for operation as hereinbefore described, valves 18 in line 19 and 42 in line 2 5 may be closed, andvalve 43 in line 44 opened. Oil then flows directly to the manifold 28 to be subdivided for furtherilow through the pipe still. Valves 45 and 46 in lines 41 and 29 are then likewise closed.

In ordinary pipe still operation, wherein vaporization occurs at an intermediate point in the iiow of the oil through the furnace or wherein a vapor is injected into the stream of oil during its passage through the furnace, difculty in the operation of the furnace frequently arises by reason of lack of uniformity of the mixture of vapor and unvaporized oil. Frequently the" further passage of the mixture takes lace in so-called slugs; that is, portions o the oil will pass through as practically disconnected liquid bodies preceded l and followed by bodies of vapor, and such condition is attended with unevenness in operating pressures, imperfect heat transfer and initiation of coke deposition. By the present invention, uniformity in operation is secured and such difficulties are substantlally avoided. Thus, the operation has been satisfactorily conducted in accordance with the present invention with outlet temperatures as high as 800 to 840 F. and with outlet pressures from slightly above atmosheric to 30 to 40 lbs. These conditions are,

owever, to be regarded as purely7 illustrative, as the invention may obviously be employed under widely varying conditions of temperration of vapors and unvaporized oil takes place, withdrawing and mixing substantially uniformly the separated vapors and unvaporized oil and iiowing the resulting mixture of vapor and unvaporized oil continuously in a restricted stream through a heating zone to impart additional heat thereto.

2. In the art of pipe still distillation of petroleum oils wherein oil is caused to flow continuously in a restricted stream through a heating zone of a furnace in which a temperature is reached at which vaporization occurs and the heated oil is caused to flow in a plurality of streams in parallel through a second heating zone of said furnace, diverting the oil after it has passed through said iirst mentioned zone into a chamber wherein separation of vapors and unvaporized oil takes place, removing the vapors and unvaporized oil separately from said chamber, dividing said vapors and unvaporized oil into a plurality of portions corresponding to the subsequent streams of flow in thesecond zone of the furnace, admixing substantially uniformly corresponding portions of said vapors and unvaporized oil and introducing said admixed portions into the second zone of the furnace for iiow therethrough in parallel streams. 3. In the art of pipe still distillation of petroleum oils, passing the oil continuously in a lrestricted stream through a heating zone, di-

' through a heating zone for further supply of heat thereto. i

4. In the-art of pipe still distillation of hy- .drocarbon oils, passing the oils continuously in a restricted stream through a heating zone, wherein a temperature is attained at which vaporization occurs, passing the oil into a chamber wherein separation of vapors and unvaporized oil takes place, separately removing the vapors and unvaporized oil therefrom, admixing steam with the separated "apors, remixing the vapors and added steam with the separated unvaporized oil to form a substantially uniform mixture, and passing said mixture continuously in a restricted stream through a heating zone for the further supplly of heat thereto.

5. n the art of pipe still distillation of petroleum oils, .passing the oil continuously in a restricted stream through a heating zone' from said chamber, adding steam to the sepi arated vapors, dividing the vapors with the added steam and the unvaporized oil into corresponding portions, remixing substantially uniformly the corresponding portions of vapors with added steam and unvaporized oil, passing the resulting admixtures continuously in restricted streams in parallel'iow through a heating zone for the supply of additional heat thereto, and subsequently reuniting the plurality of streams.

6. In the art of pipe still distillation of petroleum oils, flowing a stream of oil through a heating zone wherein it is raised to a temperature at which vaporization occurs, directing the oil into a chamber wherein separation of vapors and unvaporized oil takes place, withdrawing and mixing substantially uniformly the separated vapors and unva-y porized oil together with added steam and flowing the resulting mixture of vapor, unvaporized oil and steam continuously in a restricted stream through a heating zone to impart additional heat thereto.

7. In the art of pipestill distillation of petroleum oils, passing the oil continuously in a restricted stream through a heated Zone, directing the oil intoan enlarged chamber in which separation of oil and vapors takes place, separately removing the vapors and unvaporized oil, supplying steam to the separated vapors to fornr a vapor mixture, dividin g the vapor mixture and unvaporized oil each into a plurality of corresponding portions, separately admixing substantially uniformly the corresponding divided portions of said vapor mixture and unvaporized oil,`

and passing.. the -resulting mixtures in parallel streams through a heating zone for further supply of heat thereto.-

8. In apparatus for thepipe still distillation of hydrocarbon oils, a furnace having a plurality of heating zones, a plurality of series-connected, heat-receiving pipes in each of said heating zones, means for supplying oil to be distilled to pass in series flow through the pipes in one zone thereof, a drum, means for discharging the oil from the pipes in said zone of the furnace into the drum wherein separation of vapors from unvaporized oil occurs, aremixer, means for separately supplying vapors and unvaporized oil from the drum to the remixer for substantially uniform admixture therein, and means for conducting a resulting mixture to thel pipes in a second zone of the furnace for flow therethrough.k

9. Ink apparatus for the pipe still distilla- Ition of hydrocarbon oils, a furnacevhaving` a plurality of heating zones, a. plurality of series connected heat receiving` pipes in a heating zone thereof, means for supplying oil vto be distilled to the pipes in said heating zone for ser-ies flow therethrough to be heated to a temperature at which vaporization takes place, a drum, means for conducting the heated oil fromthe pipes in said heating zone through said drum, wherein separation of vapors and unvaporized oil vtakes place, means for separately withdrawing vapors and unvaporized oil from said drum, means for subdividing the withdrawn vapors and unvaporized oil into corresponding portions, means for remixing the corresponding subdivided portions of vapors and vaporized oil each to form a substantially uniform mixture, and means for flowing the resulting mixtures in parallel streams through pipes in' a second heating zone of the furnace whereby the mixtures receive additional heat.

10. In apparatus for the pipe still distillation of hydrocarbon oils, a furnace having a plurality of heating zones, a plurality of series connected heat receiving pipes in a heating zone thereof, means for supplying oil to be distilled to the pipes in said heating zone for series flow therethrough t0 be heated to a temperature at which vaporization takes place, a drum, means for conducting the heated oil from the pipes in said heating zone through said drum, wherein separation of vapors and unvaporized oil takes place, means for separately withdrawing vapors and unvaporized oil from said drum, means for subdividing the withdrawn vapors and unvaporized oil into corresponding portions, means for remixing the corresponding subdivided portions of vapors and vaporized oil each to form a substantially uniform mixture, and means for flowing the resulting mixtures in parallel through pipes in a second heating zone of the furnace whereby the mixtures receive additional heat, and means for subsequently reuniting said oil mixtures.

11. In apparatus for the pipe still distillation of hydrocarbon oils,`a furnace having a plurality of heating zones, a plurality of -series connected yheat receiving pipes in a lll! for separately removing vapors and unvaporized oil from the drum and; directing them to said vapor and oil manifolds respectively, for subdivision and supply to said remixers, heat receiving tubes arranged in a second heating zone of the furnace for parallel flow of oil in a number of streams corresponding to the number of said remixers, means for conducting the oil mixtures from the remixers to said last mentioned tubes, whereby the remixed oil and vapors are caused to flow in parallel streams through said tubes in said last. mentioned heating zone for the supply of additional heat thereto. i

12. In apparatus for the pipe still distillation of hydrocarbon oils, a furnace having a plurality of heating zones, a plurality of serieslconnected heat receiving pipes in a heating zone thereof,- means for supplying oil to be distilled to the pipes in said heating zone for series flow therethrough to be heated to a temperature at which vaporization takes place. a drum, means for conducting the heated oil from the pipes in said heating section through said drum, wherein separation of vapors and unvaporized oil takes place; va-

por and oil manifolds, each having a like number of outlets, remixers to which corresponding 'outlets from the vapor and oil manifolds respectively are connected, means for separately removing vapors and unvaporized oil from the drum and directing them ro said vapor and oil manifolds respectively, for subdivision and supply to said remixers,

heat receiving tubes arranged in a secondheating zone of the furnacefor parallel flow of oil 1n a number of streams corresponding to the number of said remixers, means for conducting the oil mixtures from the remixers to said last mentioned tubes, whereby the remixed oil and vapors are caused to vfiow in parallel streams through said tubes in said last mentioned heating zone for the supply of additional heat thereto,' and means 4for subsequently lcombining said parallel streams.

' 13. In apparatus for the heating of hydrocarbon oils, means for flowing the oil to be heated in a continuous stream through a heating zone wherein a temperature is attained at which vaporization occurs, a sep-. arating chamber, means for discharging the heated oil into said separating chamber to effect separation of vapors and unvaporized oil therein, means for separately removing the vapors and unvaporized oil from said chamber, a remixer, means for supplying the separated vapors and unvaporized oil to said remix r, for substantially uniform admix- Y ture therein, and means for flowing the resulting mixture continuously in a restricted stream through a heating zone wherein additional heat is supplied thereto.

14. In apparatus for the heating of hydrocarbon oils, means for flowing the oil to be heated in a continuous stream through a heating zone wherein a temperatureis attained at which vaporization occurs, a separating chamber, means for discharging the heated oil into Asaid separating chamber to effect separation of vapors and unvaporized oil therein, means for separately removing the vapors and unvaporized oil from said chamber, a remixer, said remixer comprising a conduit portion and a jet portion extending to said conduit portion, means `for supplying the withdrawn vapors to the conduit portion of the remixer, means for supplying the unvaporized oil to the jet portion of the remixer, whereby substantially uniform admixture of the unvaporized oil and vapors is effected, and means for flowing the resulting mixture continuously in a restricted stream through a hea ting zone for the further supply of heat thereto.

15. In the art of pipe still distillation of petroleum wherein the oil flows in a restricted stream through a heating zone, is brought therein to `vaporizing temperature, and the oil and vapors continue their travel in a restricted stream through the heating zone for the imparting of additional heat thereto, the steps of diverting the stream of oil products from the heating zone at an intermediate point where vaporization hasoccurred, separating vapors and unvaporized oil, remixing them to form a uniform mixture of vapor and oil and returning the mixture to the heating zone to continue its passage through the remainder thereof.

In testimony whereof I have hereunto set my hand this 27th day of February, 1928.

GEORGE W. WATTS. 

